Adrian2627 wrote:IF you can't trust your exhaust shop not to flog your car can you trust them to do a good job on your exhaust.
True. However I'm not sure how the skills of the shop to do a good job on your exhaust system relate to whether or not they take one's car out for a flogging? As they could be the best exhaust shop in the world but may not have the best ethics when it comes to their behaviour while in possession of the car.
But to OP, just request no road testing after the work, and if there is any paperwork to fill out (ie- your name, contact info, car details, etc), be sure to have them write down the odometer reading on the form (as well as writing it down for yourself) before you leave it with them. This will reduce any 'he said/she said' issues when you come to pick it up and the odometer reading has increased.